Section IV: Harvesting

The information below, is an excerpt from the "Recommendations for Coffee Berry Borer Integrated Pest Management in Hawai‘i 2016" document. The complete document can be found here.

A. Pre-harvest Strip Pick

Often, the first round of coffee harvested will yield very little marketable coffee and is of lesser quality than main-round harvested coffee. Avoid leaving these first-round cherry and raisin on the trees. These materials will serve as a reservoir from which CBB will emerge and infest subsequent rounds.
  • The first round of harvest often has a high level of CBB and may be treated as a sanitation strip-pick if all mature green, color-break, ripe, over-ripe, and raisin cherry are picked.
  • Process or destroy all fruit from this first-round harvest.

B. Main Harvest

1. Picker training
Coffee cherry and raisins left in the trees and on the ground could harbor CBB and become reservoirs for the next season. Coffee farmers should supervise pickers and impress upon them the importance of efficient harvesting and removing all ripe and dropped fruit. Farmers may combine performance goals with economic incentives such as not hiring the picker again, paying for greens and raisins, and hourly pay.
  • Pick any over-ripe and raisin cherry when harvesting.
  • Pick up dropped cherry from the ground, if possible.
  • Avoid discarding green berries, over-ripe cherry, and raisins from the picking basket onto the ground.
    • Leave in the picking basket or discard in a separate container.
    • Small amounts may be discarded in a container with soapy water.
  • Harvests can be pre-processed by adding a sorting stage, such as floating to remove reject coffee, before delivery to the mill.

2. Harvest interval or frequency
Interrupt the CBB breeding cycle with frequent and complete harvests. Coffee farmers are encouraged to avoid a harvesting interval of more than a month, which will allow CBB in berries to mature and escape.
  • A harvest interval of 2–3 weeks is ideal for CBB control.
    • A longer harvest interval will increase the number of remaining raisin and over-ripe cherry.
    • Harvest color-break to red, raisins, and over-ripe cherries.
  • Harvest promptly and as often as possible.
  • Avoid an interval length that would allow over-ripe cherry to fall to the ground.

3. Harvest bags
When infested cherries are placed in bags, CBB will escape and can be transferred back to the field. Lining the inside of the burlap bag with a plastic bag is effective at minimizing the number of escapes.
  • Tie bags shut at harvest to avoid the escape of CBB and re-infestation of the field.
  • Avoid keeping bags in the field in the sun all day.
    • Take bags to the wet mill as soon as possible.
    • Do not move cherry in bags to clean areas within the farm, especially if bags are not closed or lined with a plastic bag.
    • Coffee left in bags in the sun will begin to rot.

C. Post-harvest

1. Contain and kill CBB in wet mill
Processors can take the following precautions to avoid infesting surrounding coffee.
  • Screen the entire wet mill or portions of it, such as the floatation and fermentation tanks, to keep CBB from escaping.
  • Maintain traps in the wet mill.
    • Traps seem to be more effective in enclosed areas.
  • Cover skin, pulp, and mucilage piles with a tarp and secure the edges.
  • Disinfest empty burlap bags:
    • Heat to 122˚F (50˚C) for at least 25 minutes [5],
    • Boil in water for 5 minutes, or
    • Soak overnight in soapy water.

2. Transportation of CBB to other fields
To prevent CBB from escaping, hitchhiking, and being released back to farms on trucks, tightly tie shut plastic-lined burlap bags, and clean coffee cherry-delivery trucks and equipment with soapy water following deliveries and before re-entering the farm.

3. Contain and kill CBB at the dry mill
  • Enclose the drying deck with plastic or screen.
  • Dry parchment to at most 10.7% moisture level.
    • CBB may still be alive, but they do not reproduce nor infest adjacent uninfested beans.
    • Rapid, mechanical drying may kill CBB.
    • Low humidity (50–60%) helps mitigate CBB by encouraging beetles to evacuate the bean.
  • Since very little CBB activity is observed in green beans, the mechanical hulling process may kill CBB, perhaps with physical crushing.
  • GrainPro® bags are good for storage, but CBB can chew through the bags.
Further reading:
[5] Gautz, L.D., and A.J. Bowles. 2012. Determining effects of time, temperature, and humidity on mortality of coffee berry borer (Hypothenemus hampei). Presented at the 24th International Conference on Coffee Science, San Jose, Costa Rica. 11-16 November 2012.
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